HiCrome™ KPC Agar Base

Intended Use

Recommended for detection of Gram-negative bacteria with a reduced susceptibility to carbapenem agents.

Composition**

Final pH ( at 25°C): 7.0±0.2

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 16.5 gram in 500 ml purified / distilled water. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. Cool to 45-50°C. Aseptically add rehydrated contents of 1 vial of Selective Mix Supplement (FD279). Mix well and pour into sterile Petri plates.

Principle And Interpretation

HiCrome® KPC Agar Base is a chromogenic medium designed for the detection and differentiation of KPC producing gram negative bacterial species without selective pre-enrichment. Carbapenems are the last line of defense against invasive or serious infections and are used to treat these life threatening infections that are caused by gram negative, drug resistant pathogens (1). Production of carbapenemase enzyme results in resistance to penicillins, cephalosporins (i.e. cefepime, ceftriaxone), carbapenems (i.e. meropenem, ertapenem) and aztreonam there by making these pathogens multi drug resistant.

Most carbapenemase producing bacteria are included in the family Enterobacteriaceae, and are thus termed as carbapenem resistant Enterobacteriaceae (CRE). Besides the Enterobacteriaceae family, rare strains of Pseudomonas aeruginosa and Acinetobacter baumannii have also be found to produce carbapenemase (1,2,3). Peptone special provides nitrogenous compounds and other essential growth nutrients. This medium can be made selective by supplementation with antibiotics for detecting microorganisms associated with hospital borne infections. Selective supplements have been added to inhibit the growth of yeast, gram positive organisms and gram negative organisms that do not produce carbapenemase. This medium is intended to be used as a screening medium. Isolates should be tested further for carbapenem susceptibility following CLSI guidelines. Indole test may be performed for the confirmation of carbapenem resistant E. coli because some rare strains of C. freundii may produce small pink to magenta coloured colonies similar to E. coli. Carbapenem resistant strains of Klebsiella, Enterobacter and Serratia species produce bluish green colonies. Acinetobacter and Salmonella species produce smooth, colourless colonies. Pseudomonas species produce colourless to light yellowish green, translucent colonies with wrinkled edges. Further biochemical tests may be needed for complete identification.

Type of specimen

Clinical samples- urine, throat swabs, lung abscess, etc.

Specimen Collection and Handling

For clinical samples follow appropriate techniques for handling specimens as per established guidelines (4,5).

After use, contaminated materials must be sterilized by autoclaving before discarding.

Warning and Precautions

In Vitro diagnostic Use only. For professional use only. Read the label before opening the container. Wear protective gloves/protective clothing/eye protection/ face protection. Follow good microbiological lab practices while handling specimens and culture. Standard precautions as per established guidelines should be followed while handling clinical specimens. Safety guidelines may be referred in individual safety data sheets.

Limitations

1. Some species may show poor growth due to nutritional variations and resistance to antibiotics.
2. Slight colour variation may be observed depending upon strains.
3. Final confirmation of suspected colonies must be carried out by serological and biochemical tests.
4. Indole test may be perform for the confirmation of carbapenem resistant E. coli because some rare strains of C. freundii may produce small pink to magenta coloured colonies similar to E. coli.

Performance and Evaluation

Performance of the medium is expected when used as per the direction on the label within expiry period when stored at the recommended temperature.

Quality Control

Appearance: Cream to yellow homogeneous free flowing powder

Gelling: Firm, comparable with 1.5% Agar gel

Colour and Clarity of prepared medium: Light amber coloured, clear to slightly opalescent gel forms in Petri plates

Reaction: Reaction of 3.3% w/v aqueous solution at 25°C. pH : 7.0±0.2

Cultural Response: Cultural characteristics observed with added Selective Mix Supplement (FD279) after an incubation at 35-37°C for 18-24 hours

Key : (*) Corresponding WDCM numbers

Storage and Shelf Life

Store between 15-25°C in a tightly closed container and the prepared medium at 2-8°C. Use before expiry date on the label. On opening, product should be properly stored dry, after tightly capping the bottle in order to prevent lump formation due to the hygroscopic nature of the product. Improper storage of the product may lead to lump formation. Store in dry ventilated area protected from extremes of temperature and sources of ignition Seal the container tightly after use. Product performance is best if used within stated expiry period.

Disposal

User must ensure safe disposal by autoclaving and/or incineration of used or unusable preparations of this product. Follow established laboratory procedures in disposing of infectious materials and material that comes into contact with clinical sample must be decontaminated and disposed of in accordance with current laboratory techniques (4,5).

Reference

1. Pillai D.R. et.al. 2009. Emerg. Infect. Dis; Vol. 15, P.827-829
2. Hindiyeth, M., et. al. 2008, J. Clin. Microbiol.; Vol. 46, p.2879 -2883.
3. Samra, Z., 2008, J. Clin. Microbiol; Vol. 146, P.3110-3111.
4. Isenberg, H.D. Clinical Microbiology Procedures Handbook 2nd Edition.
5. Jorgensen, J.H., Pfaller, M.A., Carroll, K.C., Funke, G., Landry, M.L., Richter, S.S and Warnock., D.W. (2015) Manual of Clinical Microbiology, 11th Edition. Vol. 1.